shocking discovery

made a shocking discovery today. i have to use a contraption called a constant passive motion machine 4 hours a day following the knee replacement. it bends your leg back up and down to help regain flexion. anyway, was lying in bed hooked up to the cpm machine and reached for my laptop, only to be greeted by a very strong shock. later just touched my foot on the cpm while holding the laptop and another zap. no shock when laptop is running on battery but i now know not to go near the laptop if it's plugged into outlet. you'd think they'd have somekind of warning label.